Statalist


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

RE: st: RE: combining many data files


From   "Matt Spittal" <Matt.Spittal@cancervic.org.au>
To   <statalist@hsphsun2.harvard.edu>
Subject   RE: st: RE: combining many data files
Date   Thu, 20 Nov 2008 14:41:42 +1100

Good call.

Matt

-----Original Message-----
From: owner-statalist@hsphsun2.harvard.edu
[mailto:owner-statalist@hsphsun2.harvard.edu]On Behalf Of Kyle Hood
Sent: Thursday, 20 November 2008 2:04 PM
To: statalist@hsphsun2.harvard.edu
Subject: Re: st: RE: combining many data files


Matt,

The problem with this approach is that you need to have all your 
datasets named correctly.  If you use the dir extended function, you can 
use a wildcard to get everything that fits some pattern.  This obviates 
the need to rename everything (which is all well and good if you have 30 
datasets, but becomes very difficult it you have 500, or need to perform 
the operation repeatedly).

Anyway, I think this very problem is the reason they put the "dir" 
function in there.

Kyle

Matt Spittal wrote:
> Mingfeng,
>
> I'm a big fan of using -foreach- for these types of problems.  The first thing is to make sure that your datasets are named in a similar way.  In the example below I have used a set of datasets called data1, data2, ..., data30.  Once that is done, you can place your -append- command inside a -foreach- loop. For instance:
>
> 	use data1, clear
> 	foreach num of numlist 2/30 {
> 		append using data`num'
> 	}
>
> This code is really just a shortcut for the following:
>
> 	use data1, clear
> 	append using data2
> 	append using data3
> 	...
> 	append using data30
>
> Other variations are possible too, see -help foreach-.
>
> -- Matt
> matt.spittal@cancervic.org.au 
>
>
> -----Original Message-----
> From: owner-statalist@hsphsun2.harvard.edu
> [mailto:owner-statalist@hsphsun2.harvard.edu]On Behalf Of Mingfeng Lin
> Sent: Thursday, 20 November 2008 1:35 PM
> To: statalist@hsphsun2.harvard.edu
> Subject: st: combining many data files
>
>
> Greetings!
>
> I am wondering if there's a straightforward way to append a large
> number of .dta files into one file using Stata? The -append- command
> seems to disallow wildcards in the file names.  I do find one method
> from UCLA's ATS website,
>
> http://www.ats.ucla.edu/stat/stata/faq/append_many_files.htm
>
> but I'm still hoping there's an easier way, or somehow getting the
> -append- command to recognize the wildcards - so that I could just
> simply type
>
> append using *.dta
>
> Thanks :)
>
> Mingfeng
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
>
> *
> *   For searches and help try:
> *   http://www.stata.com/help.cgi?search
> *   http://www.stata.com/support/statalist/faq
> *   http://www.ats.ucla.edu/stat/stata/
>   


-- 
Kyle Hood
Department of Economics
Yale University
New Haven, CT
website: http://www.econ.yale.edu/~kkh25

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2014 StataCorp LP   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index